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From: "J . A . Magallon" <jamagallon@able.es>
To: Ying Chen <yingchenb@hotmail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: threads
Date: Wed, 7 Mar 2001 01:07:34 +0100	[thread overview]
Message-ID: <20010307010734.C1132@werewolf.able.es> (raw)
In-Reply-To: <F41oVQAiEGKROptzzpY000014a6@hotmail.com>
In-Reply-To: <F41oVQAiEGKROptzzpY000014a6@hotmail.com>; from yingchenb@hotmail.com on Wed, Mar 07, 2001 at 00:55:55 +0100


On 03.07 Ying Chen wrote:
> 2. We ran multi-threaded application using Linux pthread library on 2-way 
> SMP and UP intel platforms (with both 2.2 and 2.4 kernels). We see 
> significant increase in context switching when moving from UP to SMP, and 
> high CPU usage with no performance gain in turns of actual work being done 
> when moving to SMP, despite the fact the benchmark we are running is 
> CPU-bound. The kernel profiler indicates that the a lot of kernel CPU ticks 
> went to scheduling and signaling overheads. Has anyone seen something like 
> this before with pthread applications running on SMP platforms? Any 
> suggestions or pointers on this subject?
> 

Too much contention ? How frequently do you create and destroy threads ?
How much frequently do they access shared-writable-data ?
How do you protect them ?

It seems like your system spents more time creating and killing threads
that doing real work.

-- 
J.A. Magallon                                                      $> cd pub
mailto:jamagallon@able.es                                          $> more beer

Linux werewolf 2.4.2-ac13 #3 SMP Wed Mar 7 00:09:17 CET 2001 i686


  reply	other threads:[~2001-03-07  0:08 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-03-06 23:55 Ying Chen
2001-03-07  0:07 ` J . A . Magallon [this message]
2001-03-07  0:40 ` your mail Don Dugger
  -- strict thread matches above, loose matches on Subject: below --
2005-11-06  6:17 threads Fabio Andres Miranda
2005-11-06  8:41 ` threads Steve Graegert
2003-12-26 15:54 threads Albert Cahalan
2003-12-29 15:37 ` threads Stephen Smalley
2004-01-21  1:11   ` threads Albert Cahalan
2004-01-21  5:09     ` threads Russell Coker
2004-01-21 13:47     ` threads Stephen Smalley
2000-11-10 15:03 threads M.Kiran Babu
2000-11-10 15:39 ` threads Matti Aarnio
2000-11-10 16:05 ` threads Reto Baettig

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